Wavelenght, index of refraction and speed

AI Thread Summary
The discussion revolves around calculating the frequency, wavelength in glass, and speed of a red helium-neon laser light with a known wavelength of 632.8 nm in air. The frequency has been determined to be 4.7 x 10^16 Hz, though there is a suggestion to verify this value due to potential unit discrepancies. For the wavelength in glass with an index of refraction of 1.50, the equation n = λ0 / λ can be used, where λ0 is the wavelength in air. The speed of light in glass can be derived from the wavelength found in part B, linking it to the refractive index. Overall, the calculations require careful application of the refractive index and understanding of light properties.
dev-hud
Messages
15
Reaction score
0
THe wavelength of a red helium-neon laser light in air is 632.8 nm.

A) what is the frequency? ( i already figured this out to be 4.7 x 10^16)

B) what is its wavelenght in glass that has an index of refraction of 1.50?( i do not know where to or if i have to plug in the refraction into an equation and if i do what equation do i use?)

C) what is its speed in the glass? ( is this then related to question B? because i do not know how now to bring in v into the equation and what the equation is. i am just confuzed)
 
Physics news on Phys.org
n=\frac{\lambda_0}{\lambda}

\lambda_0 is the wavelength in air.

Part c should be easy once you have part b.
 
dev-hud said:
A) what is the frequency? ( i already figured this out to be 4.7 x 10^16)

Btw, you might want to double check that. If your units are Hz, I think you are a couple orders of magnitude off.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top